The aim of this research proposal is to understand how the sex-linked nature of particular behaviors and activities affects people's cognitions, interest, and performance on them. Three studies, two experimental and one survey, are proposed to address the following questions: (1) How do people's cognitions, motivation and behavior on sex-linked activities vary? (2) How does the use of sex-linked tasks affect the outcome of research on social behavior? It is posited that sex-linked activities have differential meaning for females and males, in terms of their prior familiarity and ego-involvement. This perspective appears fruitful, as sex-linkage effects are stereotypic in nature. Familiarity and ego-involvement are closely related to cognitive-developmental theory, and the way in which people learn and adopt the currently prevailing standards of their society. It is argued that sex-linkage effects essentially entail self-fulfilling prophecies by which sex-role stereotypes are perpetuated. It is anticipated that the greater precision of considering "sex differences" in terms of the sex of person/sex-linkage of task interaction will (a) enhance knowledge of the mechanisms underlying sex differences; (b) eliminate task biases in current research on social behavior; and (c) point the direction for remediation or intervention by eliminating arguments based on inherent or immutable factors.